VPN: Not Just an “On” Button

For many users, a VPN is simply an “On” button. However, when it comes to building your own secure tunnel, it’s important to understand its architecture. OpenVPN is based on two key ideas: the client-server model and Public Key Infrastructure (PKI).

The Client-Server Model

The concept is simple:

• Server — the entry point into your secure network. It constantly “listens” for incoming requests and is ready to accept connections.
• Client — your device (laptop, phone) that initiates the connection to the server.

Once the server and client “agree,” a secure tunnel is created between them, and all traffic passes through it.

The Heart of Security: Public Key Infrastructure (PKI)

This is the most important and complex concept of OpenVPN. It ensures security and trust between the parties. Think of it as a system of “digital passports” and “visas”:

1. Certificate Authority (CA): The “passport office” that issues and signs all certificates. Both the server and every client trust only what is signed by this authority.
2. Server Certificate: The “passport” of your server. When a client tries to connect, the server shows its certificate, proving it really is who it claims to be.
3. Client Certificates: Each client has its own unique “passport.” The server only accepts the connection if this “passport” is signed by the trusted CA.

Thus, PKI guarantees that only devices you’ve granted a “visa” can connect to your network, and that they’re connecting to the real server, not an imposter.

Deployment Options

There are two main approaches to setting up an OpenVPN server:

1. Manual Setup: The classic method, giving you full control. You generate all certificates yourself and write configuration files. This path is ideal for those who want to thoroughly understand how everything works and are willing to invest time in learning.

2. Automated Setup: For those who value time, there are solutions that automate the entire process.

   • Simple scripts: For example, openvpn-install, which asks you a few questions and deploys a ready-to-use server with all keys and configurations in about 10 minutes.
   • Specialized solutions: Software like OpenVPN Access Server, which provides a convenient web interface, allowing you to manage users and the server without touching the command line.

Conclusion

Your choice of method depends on your goals. If you want to truly understand the essence, go for manual setup. If you just need a working and reliable VPN that can be deployed and managed quickly, use automated solutions. Either way, you’ll be relying on the trusted and time-proven OpenVPN protocol.